JPS62268809A - Splittable synthetic fiber and production thereof - Google Patents

Abstract

PURPOSE:To provide a synthetic fiber having a multiply flexed cross-sectional form having two or more V-shaped parts laterally linked with each other, having a specific dimension and easily giving a soft-touch pile of splitting the tip end of the fiber by brushing or polishing. CONSTITUTION:The spinnered used in the present process has two or more V-shaped slits having a bent angle alpha of 80-100 deg. and linked with each other. Circular holes are bored at the end parts and the bent part. The ratio H/D (D is diameter and H is distance between centers) is 1.5-3.0 and the ratio D/L (L is width of the slit) is 1.5-3.0. A thermoplastic compound is extruded through the spinneret in molten state, drawn and heat-treated under tension at a temperature within the range of formula. The objective fiber produced by the above process is composed of two or more V-shaped parts having a bent angle alpha of 80-100 deg.C, the ratio d/l (d is diameter of bulged part and lis minimum width of constricted part) of 1.5-2.5 and a distance h between the centers of adjacent bulged parts of 1.5-3.0 times the diameter of the bulged part.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a synthetic fiber suitable for carpets, high piles, moquettes, etc., and a method for producing the same.
More specifically, the tips of the fibers are easily split during normal finishing processes such as brushing and polishing.
The present invention relates to a synthetic fiber suitable for obtaining a pile-like material having a soft touch surface and appropriate elasticity, and a method for producing the same.

<While prior art and inventions attempt to solve ffl,
a> Traditionally, synthetic fibers used for soft velor carpets or pile yarns such as single pile yarns are made of multiple fibers with different deniers and different cross sections in order to achieve flexibility, stiffness, and supple texture. Although these pile yarns are a mixture of seeds, these pile yarns do not necessarily satisfy the above-mentioned quality performance.

In addition, in recent years, Japanese Patent Application Laid-open No. 55-128044 and No. 56-
As seen in Publication No. 107044, fur trimming hair 11
A method has been proposed in which a special flat cross-section yarn is used as the i-fiber and the multi-fiber tip is divided by treating this yarn with a chemical, but in this method, a chemical is applied to the pile tip in the final stage and the pile is finely divided. This method has problems such as poor production efficiency and the possibility of streaks, and the polymers that can be used are limited to special ones, resulting in high costs and lack of versatility. However, it cannot be said that it is sufficient.

On the other hand, improvement of texture, flexibility, etc. by flattening the cross section can be achieved by methods other than those described in the above-mentioned published patent application.
23330 and Utility Model Application Publication No. 57-76580, etc., it has been suggested that the fibers can be used as cut pile carpets. However, the fibers obtained by these methods have the flexibility characteristic of flat cross-section yarns. Although it exhibits a soft texture and a certain effect, it is unsatisfactory in terms of resilience under pressure, firmness, and smooth gloss, which are essential characteristics of carpets and high piles.

Furthermore, as a fiber whose cross section is bent,
The series of slit shapes described in Publication No. 30392 is 9.
However, this fiber has the disadvantage that the end of the slit part is easily damaged during the process of forming a spun yarn into a pile yarn, and the tip of the pile becomes disordered, resulting in a deterioration in appearance. be.

Means for Solving the Problems> The present invention solves the problems of the prior art and provides a synthetic fiber suitable for obtaining a pile-like material having a soft touch surface and appropriate elasticity, and a method for producing the same. This is what we provide.

That is, in the present invention, the cross-sectional shape of the fiber is V-shaped, as shown in FIGS. It has a multi-bent flat shape formed by connecting two or more in the lateral direction, and the diameter d of the circular bulge is equal to the minimum width t of the constriction.
The distance between the centers of adjacent bulges is 15 to 3.0 times the diameter d, and the angle α of the V-shaped bent part is 80 to 100°. It is a splittable synthetic fiber characterized by: The present invention also provides a means for producing this splittable synthetic fiber, in which the cross-sectional shape is as shown in FIGS.
II circular shape, the circular parts are connected by a linear slit with a width Lm, and the ratio of the diameter to the slit width is D/L.
is 1.5 to 3.0, the ratio H/D of the distance H between the centers of adjacent circular parts and the diameter D+w is 1.5 to 3.0, and the angle θ of the bent part is 80 After spinning a melt of a thermoplastic synthetic polymer using a spinneret having pores in the form of two or more V-shaped pores connected in the transverse direction with a diameter of 1,000 mm, this is stretched to form a fiber of (Tt + 40) degrees Celsius or more. It is characterized by heat treatment under tension at (Tm-40)°C (where Tr and - respectively indicate the glass transition temperature and melting point of the thermoplastic synthetic polymer).

Examples of the thermoplastic synthetic polymer used in the present invention include polyesters, polyamides, polyolefins, etc., and polyesters containing polyethylene terephthalate or polybutylene terephthalate as a main component are particularly preferred. Modifiers such as matting agents, pigments, flame retardants, fragrances, and ultraviolet absorbers may be added to these synthetic polymers, or a third component may be copolymerized.

The synthetic fiber of the present invention preferably has a denier of 3 to 25, particularly 5 to 15 denier. If the hair is thinner than 3 denier, if it is divided, it will be too thin and weak, and the ends of the pile will be disordered, deteriorating the appearance. Further, if the pile is thicker than 25 denier, the thick denier remains even after division, and the soft touch on the surface of the pile-like object is insufficient.

The fiber cross-sectional shape of the present invention is one in which two or more 7-shaped shapes are connected, and 2 *KV-shaped shapes [Figure 1 (a))%2.
It is best to have 5 pieces [infant form] or 3 pieces [Fig. 1 (b)] connected and 9 pieces. When the number of 7-shaped pieces is 1 or 1.5 (N-shaped), the number of divisions is small, and the surface soft touch of the pile material is insufficient. Diameter d and width of the constriction! The relationship between the distance between the centers of the bulges is d/g is 1.5 to 2.5, and h/d is 1.
．． It is necessary to be in the range of 5 to 3.0 (7), and d
/l, h/d is smaller than 1.5, it is difficult to split the fibers, and the object of the present invention cannot be achieved.
If the diameter is larger than 2.5, after the fibers are divided, a thick round part and a small flat part are likely to be formed, and the latter is not too thin and becomes weak and damaged, degrading the appearance of the pile. Furthermore, if h/d is greater than 3.0, the fibers will be cleaved irregularly and in large numbers in the flat portions, and the fibers will quickly become too thin, resulting in a deterioration in the appearance of the pile, which is undesirable.

The angle α formed by the V-shaped bent portion of the fiber cross-sectional shape of the present invention is 8
0 to 100°, but if α is smaller than 800, the pile will be too stiff, and if α is larger than 100°, the pile will become too stiff, both of which are undesirable. K that obtains is not suitable.

During the manufacturing process of the ◆ fiber of the present invention, at least one of the constrictions of the fiber cross section forms a crack, but this crack enlarges during the process of brushing or polishing the pile, and the tip of the fiber splits. becomes.

Figure 1 shows the pores of an example of a spinneret used to obtain the fiber cross-sectional shape of the present invention. D is 1.5~
3.0, θ needs to be between 80 and 100°. If these conditions are not satisfied, the fiber cross-sectional shape of the present invention cannot be obtained by the above-described method.

In addition, in the present invention, the fiber after drawing is (ry-4-4o)"
C~(Tm-40)"C (7'? T2 is the glass transition temperature, Tm is the melting point) is heat treated under tension,
When the temperature is lower than (Tf + 40)'C, cracks are difficult to form in the fiber cross section, and when it is higher than (Tm - 40)'C, fibrillation progresses too much and the twill fibers become weak, causing problems in the spinning process and pile. This is undesirable because it is damaged by plan song or polishing and reduces the appearance of the pile.

Next, the present invention will be explained using examples. In addition, the intrinsic viscosity [η] in the examples is a value measured at 30° C. in a mixed solvent of equal weights of phenol and tetrachloroethane.

Example 1 Polyethylene terephthalate with an intrinsic viscosity [η] of 0.6241/liter was prepared in the shape shown in Figure 1 (a) with D=0.2.
5vz, L=0.11+IJ, H=0.75v
Melt spinning was carried out using a spinneret having 130 pores with s, θ = 900, and stretched in a water bath according to a conventional method at 180°C.
The fibers were subjected to tension heat treatment using a roller, crimped, and then cut into stable fibers with a fineness of 12 denier. The cross-sectional shape of this fiber is as shown in Fig. 2 (a) and Fig. 3, d/l = 2.0, h/d = 1.8.
, α=90°, and there was a crack in the constriction.

After dyeing this staple fiber according to a conventional method,
It is mixed with 10 denier polyethylene terephthalate fiber with a round cross section in a 1:1 ratio and spun, and this is used to create cut pile carpet.

When this carpet was tufted and then polished, the 0 carpet pile was observed under a microscope. The round cross-section fibers were unchanged, but most of the special cross-section fibers were 0.1 to 1. It was cleaved and subdivided into 2 to 4 pieces with a length of O0. The surface of this carpet was soft to the touch and had a good texture with appropriate elasticity.

Example 2 Intrinsic viscosity [η] is 0.88 dll? The polybutylene terephthalate melt has a shape as shown in Figure 1 (b) with D = 0.
．． 2 fins, L = 0.08 dew, H = 0.5 sieve, extruded from a spinneret with 150 pores of θ = 95°, 800
After rolling it up for 7 minutes, it was stretched in a 75°C water bath for 16 minutes.
The fibers were heat-treated under tension using a heated roller at 0° C., crimped using a crimper, and cut into 6-denier stable fibers. The cross-sectional shape of this fiber is as shown in Figure 2 (b), with d/l=2.4, h/d-2,
3. At α-95°, all fibers had a crack at at least one place at the waist.

After dyeing this staple fiber, it was mixed in a 1:1 ratio with a polybutylene terephthalate staple fiber having a round cross section of 3 deniers to obtain a spun yarn. A high pile was made using this spun yarn and polished. The obtained product had appropriate elasticity and a good texture with a soft touch surface. When the tips of the fibers that make up the pile yarn were observed under a microscope, no changes were seen in the round cross-section fibers, but the special cross-section fibers had a 0.0-degree change from the fiber tip.
It was cleaved and subdivided into 2 to 5 pieces with a length of 1 to 0.6 m.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an example of a spinneret used in the present invention;
FIGS. 2 and 3 show cross-sectional views of an example of the fiber of the present invention.

Claims (1)

[Scope of Claims] 1) A fiber cross-sectional shape consisting of two or more V-shapes connected in the lateral direction, in which the end portion and the bent portion form a circular bulge and the straight portion forms a constriction. It has a bent flat shape,
The diameter d of the circular bulge is 1.5 to 2.5 times the minimum width l of the constriction, and the distance h between the centers of adjacent bulges is 1.5 to 3.0 times the diameter d. A splittable synthetic fiber characterized in that the angle α of the V-shaped bent portion is 80 to 100°. 2) The cross-sectional shape is circular with a diameter Dmm at the end part and the bent part, and the circular parts are connected by a linear slit with a width Lmm, and the ratio D/L of the diameter and slit width is 1.5. ~3
．． 0, the ratio H/D of the distance Hmm between the centers of adjacent circular parts and the diameter Dmm is 1.5 to 3.0, and the angle θ of the bent part is 80 to 100°. After spinning a thermoplastic synthetic polymer melt using a spinneret having two or more horizontally connected pores, this is stretched;
(Tg+40)℃～(Tm-40)℃ [However, Tg, T
m represents the glass transition temperature and melting point of a thermoplastic synthetic polymer, respectively.